Gardening in the late summer and early fall can barely be called working. Cooler, crisper days and the knowledge that time outdoors will soon be limited gives every task a bittersweet flavor. That said, there’s still plenty to do, so don’t waste time on unnecessary chores. We’ve taken the work out of deciding what to do for you. No need to thank us; just have fun out there.
Plant trees, shrubs, and perennials. Fall is the perfect time to plant; the weather is cooler, rain more plentiful, and the soil still warm. Plants put out terrific root growth, giving their above-ground growth a head start in spring.
Clean up foliage from roses, peonies, and any plant with diseased foliage. But don’t compost; the pile may not get hot enough to cook the pathogens.
Get a soil test. The labs aren’t as busy, so you’ll get your results sooner, and once you incorporate the amendments (except for nitrogen; apply that in spring), the soil will settle over the winter.
Divide spring-blooming plants such as iris, brunnera, dianthus, lamium, and primrose. Later bloomers that can also be divided include black-eyed Susans, geraniums, daylilies, hostas, coneflowers, and yarrows.
Don’t do that:
Don’t cut down dead stalks of purple coneflower, black-eyed Susans, sunflowers, and other plants whose seeds or berries feeds birds through the winter.
Don’t remove logs, brush piles, or dead groundcover; leave it for beneficial insects such as spiders, solitary bees, lady beetles, and other beetles to overwinter in.
Don’t plant these trees in fall: magnolias, birches, firs, hemlocks, ginkgos, or ornamental pears. They root slowly, so they may not survive the winter.
Don’t put your leaves out with the trash. Either bag them and let them break down over the winter, or go over them with the lawnmower and rake the shreddings into your flower borders.